Heat Dissipating Device and Method of Fabricating the same

ABSTRACT

A heat dissipating device includes thermal conductive pipes and a plurality of thermal fin modules. Each thermal fin module made by pressing and stacking is mounted on the thermal conductive pipes. A retainer is located between each two thermal fin modules to compress the thermal fin module, so that a distance between two fins of the thermal fin module is reduced. Finally, a fixing plate is set above the last thermal fin module on the thermal conductive pipes to fix the thermal fin modules securely engaged with the thermal conductive pipes. Therefore, the assembled heat dissipating module could not be loosed and deformed during delivery and the engaging contact between the fins and the thermal conductive pipes are enhanced, so to increase the heat dissipating effect of the heat dissipating module.

This application is a divisional application of U.S. patent applicationSer. No. 11/297,402, filed on Dec. 9, 2005.

5 BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipating device and a methodof fabricating the same, and particularly relates to a method offabricating a heat dissipating device including at least two thermal finmodules capable of being stably fixed on thermal conductive pipes.

2. Description of Related Art

Usually, in order to increase the heat dissipating speed, multiplethermal conductive pipe is passed through the fins of a thermal finmodule. Therefore, the heat generated from a heat source could bedissipated through the thermal conductive pipe and the thermal finmodule.

During assembling a heat dissipating device, first, a plurality of finsare pressed and stacked together to make the thermal fin module andthrough holes are correspondingly formed on the fins of the thermal finmodule. Then, annular walls are respectively formed surrounding thethrough holes, and the thermal conductive pipes are passed through thefins. The annular wall of a lower fin is embedded into the gap betweenthe thermal conductive pipe and the annular wall of an upper fin.Therefore, the fins are stacked together to be engaged with the thermalconductive pipes.

However, the structure assembled in the manner mentioned above is notcompact enough, such that the fins could loose from the thermalconductive pipe or deform during delievery. Thus, the contact area ofthe thermal conductive pipes with the fins of the thermal fin module isreduced, so that the heat dissipating effect is not good. It isnecessary to improve the assembling step to increase the contact area ofthe thermal conductive pipe with the fins and to induce an adhesivematerial so that the adhesion between the fins and the thermalconductive pipes can be improved.

SUMMARY OF THE INVENTION

The present invention is to provide a heat dissipating device. The heatdissipating device comprises at least two thermal fin modules, at leastone thermal conductive pipe, a retainer and a fixing plate. Each thermalfin module is made of a plurality of fins by pressing and stacking.Through holes are formed on each fin of the thermal fin modulecorresponding to the thermal conductive pipes. The fixing plate is seton the top of two thermal fin modules, wherein the fixing plate isthicker than each of the fins of the thermal fin module, and holes areformed on the fixing plate for the thermal conductive pipes to passthrough. Therefore, the fins of the thermal fin module can be fixedlymounted with the thermal conductive pipes by the fixing plate.

The present invention is also to provide a method of fabricating athermal fin module. First, a first thermal fin module made by pressingand stacking a plurality of fins is mounted on thermal conductive pipes.Next, a retainer is attached to the top surface of the first thermal finmodule, and a compressing force is exerted on the first thermal finmodule. Thereafter, a second thermal fin module made by pressing andstacking a plurality of fins is mounted on thermal conductive pipes tothe first thermal fin module. Then, a fixing plate is set above thesecond thermal fin module on the thermal conductive pipes. Finally, thefixing plate set on the thermal fin module makes and the thermal finmodule securely fixed on the thermal conductive pipes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a heat dissipating device accordingto the first embodiment of the present invention;

FIG. 2 is a cross-section view illustrating that a first thermal finmodule is mounted on thermal conductive pipes according to the firstembodiment of the present invention;

FIG. 3 is a partially magnified schematic drawing of FIG. 2;

FIG. 4 is a perspective view showing a retainer being mounted on thethermal conductive pipes to the first thermal fin module;

FIG. 5 is a perspective view showing a second thermal fin module ismounted on thermal conductive pipes to the first thermal fin module;

FIG. 6 is a perspective view illustrating that a fixing plate will bemounted on the thermal conductive pipes to the second thermal finmodule;

FIG. 7 is a cross-section view illustrating the fixing plate mounted onthe thermal conductive pipes;

FIG. 8 is a partially magnified schematic drawing of FIG. 6; FIG. 9 is across-section view of a heat dissipating device according to the secondembodiment of the present invention;

FIG. 10 is a cross-section view of a heat dissipating device accordingto the third embodiment of the present invention;

FIG. 11 is a perspective view showing a heat dissipating deviceaccording to the fourth embodiment of the present invention; and

FIG. 12 is a perspective view showing a heat dissipating deviceaccording to the fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Please refer to FIGS. 1-12. According to the present invention, a methodof fabricating a heat dissipating device comprises the following steps:

a) mounting a first thermal fin module 10 made by pressing and stackinga plurality of fins 1 on thermal conductive pipes 2;

b) setting a retainer 5 on the top surface of the first thermal finmodule 10, and compressing downward the thermal fin module 10;

c) mounting a second thermal fin module 10′ made by pressing andstacking a plurality of fins 1′ on thermal conductive pipes 2 to locateabove the first thermal fin module 10;

c) mounting a fixing plate 4 above the second thermal fin module 10′ onthe thermal conductive pipes 2; and

d) setting the fixing plate 4 on the thermal fin module 10′ to make thefirst and the second thermal fin modules 10 and 10′ securely fixed onthe thermal conductive pipes 2.

In FIG. 1, the thermal conductive pipes 2 pass through the fins 1, 1′with a thickness of less than 0.2 mm. The fins 1, 1′ are used todissipate heat from the thermal conductive pipes 2. The fins 1, 1′ andthe thermal conductive pipes 2 are tightly connected, so as to reduceany gap between the fins 1, 1′ and the thermal conductive pipes 2. Thethermal conductive pipes 2 can be water pipes or heat pipes. In theembodiment, the thermal conductive pipes 2 are preferably the heatpipes.

In the first preferred embodiment, the first and the second thermal finmodules 10, 10′ comprising a plurality of fins 1, 1′ are provided.Through holes 11, 11′ are formed on each of the fins 1, 1′ correspondingthe locations of the thermal conductive pipes 2. Annular walls 12, 12′with tapered shape are formed on each of the through holes 11, 11′ by adrawing process during forming the through holes 11, 11′. Each annularwall 12, 12′ comprises a taper portion 121, 121′ surrounding the top ofthe through holes 11, 11′ and a pressing portion 122, 122′ extendingfrom the narrow top of the taper portion 121, 121′ (as shown in FIG. 3).After assembling the fins 1, 1′ to form the thermal fin module 10, 10′,each of the through holes 11, 11′ of an upper fin is seated on each ofthe pressing portions 122, 122′ of a lower fin. In addition, the thermalconductive pipes 2 are vertically installed on a thermal base 3, so asto form a heat dissipating device 100.

The retainer 5 is mounted on the thermal conductive pipes 2 to locatebetween two thermal fin modules 10 and 10′. A plurality of holes 51 areformed on the retainer 5, such that the thermal conductive pipes 2 couldpass through the holes 51, respectively. A fixing plate 4 is installedon the top of the second thermal fin module 10′ after the thermalconductive pipes 2 pass through two thermal fin modules 10 and 10′. Thefixing plate 4 is thicker than each of the fins 1, 1′. A plurality ofholes 41 are formed on the fixing plate 4, such that the thermalconductive pipes 2 could pass through the holes, respectively.

In FIG. 1 and FIG. 2, during the step of installing the first thermalconductive pipes 2 through the thermal fin module 10, the thermalconductive pipes 2 are passing from the wide base of the taper portions121 of the annular walls 12 through the though holes 11 of the stackedfins 1. Since the narrower pressing portion 122 which has a sizeslightly smaller than the size of the thermal conductive pipes 2, afterthe fins are sequentially mounted to the thermal conductive pipes 2, thedistance between the fins 1 is slightly prolonged during the passingstep. Thus, the through holes 11 of the fins 1 and the thermalconductive pipes 2 are not tightly contacted, as shown in FIG. 3.

Preferably, a layer of thermal conductive material (not shown) is pastedon the surface of the thermal conductive pipes 2 before passing thethermal conductive pipes 2 through the through holes 11. The thermalconductive material comprising dense polymers, such as silicone oil,mineral oil, or polyethylene glycol (PEG), lubricates the thermalconductive pipes 2 and the through holes 11, such that the thermalconductive pipes 2 could pass through the through holes 11 easily.Furthermore, the dense polymers can fully fill up the gap between thethermal conductive pipes 2 and the pressing portions 122 of the fins 1,so as to increase the adhesion.

In FIG. 4, the retainer 5 is fixed on the upper layer of the fins 1. Acompressing force is induced from the retainer 20 to press on the fins1, such that the pressing portion 122 of each lower fin is embedded intothe gap between the thermal conductive pipes 2 and taper portion 121 ofeach upper fin, as shown in FIG. 8. Thus, the distance between two fins1 is reduced, and the adhesion between the thermal conductive pipes 2and the fins 1 is improved.

In FIG. 5, when the retainer 5 fixes the first thermal fin module 10 onthe thermal conductive pipes 2, the second thermal fin module 10′ willbe similarly mounted on thermal conductive pipes 2. The distance betweenthe fins 1′ is slightly prolonged during the passing step. Thus, thethrough holes 11′ of the fins 1′ and the thermal conductive pipes 2 arealso not tightly contacted.

In FIG. 6 and FIG. 7, the fixing plate 4 is set on the thermalconductive pipes 2 to install the fixing plate 4 on the top of thesecond thermal fin module 10′ so that the pressing portion 122′ of eachlower fin is embedded into the gap between the thermal conductive pipes2 and taper portion 121′ of each upper fin, as shown in FIG. 8. Thus,the distance between two fins 1′ is also reduced.

Similarly, a layer of thermal conductive material (not shown) is pastedon the surface of the thermal conductive pipes 2 before passing thethermal conductive pipes 2 through the through holes 11′. As such, theadhesion between the thermal conductive pipes 2 and the fins 1 is alsoimproved and the thermal fin module 10, 10′ and the thermal conductivepipes 2 are fixed and assembled. Moreover, an adhesive material ispreferably pasted covering the sidewall of the holes 41 and 51 of thefixing plate 4 and the retainer 5, respectively , such that the adhesionbetween the fixing plate 4 and the fixing plate 5 and the thermalconductive pipes 2 is improved.

In FIG. 9, a cross-section view of the second embodiment of the presentinvention is shown. In the second embodiment, one more fixing plate 4 isfurther installed below the lower surface of the first thermal finmodule 10. Thus, the fixing plates 4 are set on the thermal conductivepipes 2 to have the thermal fin modules 10 and 10′ sandwichedtherebetween.

In FIG. 10, a cross-section view of the third embodiment of the presentinvention is shown, where there are three thermal fin modules 10, 10′and 10″ provided. First, the fixing plate 4 is mounted on the thermalconductive pipes. Then, the first thermal fin module 10 is set on thethermal conductive pipes 2 by compressing. Next, the retainer 5 is fixedon the top of the surface of the first thermal fin module 10, and acompressing force is induced from the retainer 5 to press on the fins 1of the first thermal fin module 10, such that the pressing portion 122of the lower fin of the first thermal fin module 10 is embedded into thegap between the thermal conductive pipes 2 and taper portion 121 of theupper fin of the first thermal fin module 10. The annular walls 12 ofthe first thermal fin 10 are more tightly engaged with the thermalconductive pipes 2 in order.

The second thermal fin module 10′ is then similarly set on the thermalconductive pipes 2. Thus, the second thermal fin module 10′ is fixed andlocated above the first thermal fin module 10. Another retainer 5 isfixed on the second thermal fin module 10′. A compressing force is againinduced from the retainer 5 to press on the fins 1′ of the secondthermal fin module 10′, such that the pressing portion 122′ of the lowerfin 1′ of the first thermal fin module 10′ is embedded into the gapbetween the thermal conductive pipes 2 and taper portion 121′ of theupper fin 1′ of the second thermal fin module 10′. The distance betweenthe fins 1′ of the second thermal fin module 10′ is thus reduced. Theannular walls 12′ of the second thermal fin module 10′ are more tightlyengaged with the thermal conductive pipes 2 in order.

The third thermal fin module 10″ is then similarly set on the thermalconductive pipes 2. Thus, the third thermal fin module 10′ is fixed andlocated above the second thermal fin module 10′. Finally, another fixingplate 4 is set on the thermal conductive pipes 2 above the third thermalfin module 10″. As a result, the first, the second and the third thermalfin module 10, 10′ and 10′‘are fixed and compressed on the thermalconductive pipes 2 by the fixing plates 4 and the retainers 5.Therefore, the annular walls of the first, the second and the thirdthermal fin module 10, 10′ and 10′’ are all more tightly engaged withthe thermal conductive pipes 2.

In the above embodiments of the present invention, the thermalconductive pipes 2 are, but not limited to, U-shaped circular tubes. Forexample, in FIG. 11, a perspective schematic view of the fourthembodiment of the present invention is shown, wherein the thermalconductive pipes 2′ are substantially U-shaped elliptic tubes. That is,the shapes of the through holes 11, 11′ of the fins 1, 1′ of the thermalfin module 10, 10′ and the holes 41 and 51 of the fixing plate 4 and theretainer, respectively, are formed in ellipse according to a crosssectional shape of the thermal conductive pipes 2′. In FIG. 12, aperspective schematic view of the fifth embodiment of the presentinvention is shown, wherein the thermal conductive pipes 2″, which canbe called as the isothermal plate pipes, have rectangular plates incross section. As such, the shapes of the through holes 11, 11′ of thefins 1, 1′ of the thermal fin module 10, 10′ and the holes 41 and 51 ofthe fixing plate 4 and the retainer, respectively, are formed inrectangle.

As mentioned above, the fins of the thermal fin module are fixed and seton the thermal conductive pipes by using the fixing plate and theretainer as a stopper, such that it prevents the thermal fin module fromloosing and deforming during delivery, resulting in improvement of theyield rate of the products. Furthermore, the pressing portions of theannular walls of the fins are embedded into the gap between the taperportions of the annular walls of the fins and the thermal conductivepipes, due to the compression by the fixing plate and the retainer;therefore, the engagements between the thermal conductive pipes and theannular walls are greatly enhanced by the increasing engaging contactareas. Thereby, the heat dissipating effect of the thermal fin module isimproved, so as to rapidly dissipate the heat of the thermal conductivepipes .

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A method of fabricating a heat dissipating device, comprising:mounting a first thermal fin module made by pressing and stacking aplurality of fins on thermal conductive pipes; setting a retainer on atop surface of the first thermal fin module, and compressing the firstthermal fin module, so as to reduce a distance between two fins of thefirst thermal fin module; mounting a second thermal fin module made bypressing and stacking a plurality of fins on thermal conductive pipes tolocate above the first thermal fin module; mounting a fixing plate abovethe second thermal fin module on the thermal conductive pipes; andsecuring the fixing plate on the second thermal fin module, so as tosecurely fix the first and the second thermal fin modules with thethermal conductive pipes.
 2. The method as claimed in claim 1, wherein aplurality of through hole are formed on the fins corresponding tolocations of the thermal conductive pipes, respectively, an annular wallwith tapered shape is formed on each through hole by a drawing process,and a pressing portion extending from a narrow top of the taper portion.3. The method as claimed in claim 2, wherein the pressing portion of alower fin is embedded into a gap between the thermal conductive pipe andthe taper portion of an upper fin during compressing the thermal finmodule, so as to reduce the distance between two fins of the thermal finmodule.
 4. The method as claimed in claim 1, wherein a layer of thermalconductive material for lubricating is pasted on the surface of thethermal conductive pipe before assembling the thermal conductive pipewith the fins.
 5. The method as claimed in claim 1, wherein a layer ofadhesive material is pasted on the sidewall of a hole formed on thefixing plate or the retainer before the fixing plate or the retainer isset on the thermal conductive pipes, so as to increase the adhesionbetween the thermal conductive pipe and the fixing plate or theretainer.